Effects of steam generator sectioning on the reliability of a nuclear power station containing a fast reactor

Adequate reliability in the individual units and in the station as a whole must be provided in order to meet current specifications for the economic performance and safety of nuclear power stations. In the case of sodium-cooled fast reactors, a current problem is to improve the reliability in the steam generators of sodium-water type. Various Soviet and foreign designs for such reactors use sectional steam generators, which raise the reliability and safety of the station because they localize possible faults caused by leaks in the SG heatexchanger tubes to a single steam-generating section. The SG sectioning makes it necessary to incorporate factors into the reliability model such as the steam generator repair strategy, the number of steamgenerating sections in one cooling loop, and the working constraints on the available unit power. The authors present a model that has been used to examine the effects of these factors on the reliability of a fast-reactor system.